Note Income taxes - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018
Income Taxes [Line Items]
Deferred Tax Assets Net	$ 993,330		$ 1,049,895
Unrecognized Tax Benefits Interest On Income Taxes Accrued	3,000		2,800
Unrecognized Tax Benefits That Would Impact Effective Tax Rate	9,800		9,000
Significant Change In Unrecognized Tax Benefits Is Reasonably Possible Amount Of Unrecorded Benefit	4,700
Recognized Tax Benefits Current Interest On Income Taxes Accrued	149	$ 151
Deferred Tax Liabilities	112,825		96,406
Deferred Tax Assets Valuation Allowance	496,642		496,307
Income Tax Expense Benefit	50,223	22,155
Popular, Inc. Holding Co.
Income Taxes [Line Items]
Deferred Tax Assets Valuation Allowance	95,000
Income Tax Expense Benefit	0	0
Other assets
Income Taxes [Line Items]
Deferred Tax Assets Net	1,000,000		1,000,000
Other liabilities
Income Taxes [Line Items]
Deferred Tax Liabilities	930		926
PUERTO RICO
Income Taxes [Line Items]
Deferred Tax Assets Net	669,000
Deferred Tax Liabilities	78,566		68,483
Deferred Tax Assets Valuation Allowance	95,334		89,852
Income Tax Expense Benefit	$ 50,223	$ 22,155
Computed income tax at statutory rates	38.00%	39.00%
UNITED STATES
Income Taxes [Line Items]
Deferred Tax Assets Net	$ 323,000
Deferred Tax Liabilities	34,259		26,814
Deferred Tax Assets Valuation Allowance	401,308		$ 406,455
Deferred Tax Assets	$ 724,000